• Journal of Wetlands Research
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• v.21 no.1
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• pp.43-56
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• 2019

Irrigated and flooded rice paddy contributes to the greenhouse gas emissions (GHG) that affect climate. This in turn affects the supply and reliability of the water needed for rice production. This dynamic makes current rice production methods foreseeably less sustainable over time while having other undesirable effects. Intermittent irrigation by a means of the system of rice intensification (SRI) and alternate wetting and drying (AWD) methods was reviewed to reduce global warming potential (GWP) from 29% to 90% depending on site-specific characteristics from flooded rice paddy and analyzed to be a promising option for enhancing the productivity of water as well, an increasingly constraining resource. Additional benefits associated with the SRI/AWD can be less arsenic in the grain and less degradation of water quality in the run-off from rice paddies. Adoption and expansion of intermittent irrigation of SRI/AWD may require costly public and private investments in irrigation infrastructure that can precisely make irrigation control, and the involvement and upgrading of water management agencies and farmer organizations to enhance management capabilities. Private and public collaboration as a means of earning carbon credit under the clean-development mechanism (CDM) with SRI/AWD for industries to meet as a part of their GHG emission quota as well as a social contribution and publicity program could contribute to adopt intermittent irrigation and rural investment and development. Also, inclusion of SRI and AWD in programs designed under CDM and/or in official development assistance (ODA) projects could contribute to climate-change mitigation and help to achieve UN sustainable development goals (SDGs).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.5
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• pp.452-460
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• 2019

Exposure to heavy metals through the consumption of contaminated seafood poses a health risk to humans. In Korea, seafood imports are increasing with consumption, with the largest increase in imported seafood coming from Russia. Peter the Great Bay and the Razdolnaya River are both major fisheries and protected areas under the Northwest Pacific Action Plan located near Vladivostok, Russia. This study analyzed heavy metal [cadmium (Cd), lead (Pb), total mercury (tHg), and total (tAs), and inorganic (iAs) arsenic] concentrations in shellfish and crustaceans collected from these areas. Except for iAs, the major toxic heavy metal concentrations of the samples met the national standards (Cd, 0.024-0.982 and 0.003-0.379 mg/kg; Pb, 0.021-1.533 and 0.002 mg/kg; tHg, 0.006-0.015 and 0.036-0.097 mg/kg). The tAs concentrations of three samples exceeded the Russian standard (5 mg/kg, wet weight), whereas the iAs concentrations were extremely low (ND-0.033 mg/kg). Compared with the provisional tolerable weekly intake (PTWI) of the Ministry of Food and Drug Safety and Joint FAO/WHO Expert Committee on Food Additives, the percentages of PTWI of Cd, Pb, and tHg were 0.239%, 0.001-0.049%, and 0.013-0.302%, respectively. These findings reveal that there is no potential health risk by heavy metals through the consumption of Russian seafood obtained in the surveyed areas.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.670-682
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• 2018

Engineered nanomaterials (ENMs) can be released to humans and the environment through the generation of waste containing engineered nanomaterials (WCNMs) and the use and disposal of nano-products. Nanoparticles can also be introduced intentionally or unintentionally into waste streams. This study examined WCNMs in domestic industries, and target nanomaterials, such as silicon dioxide, titanium oxide, zinc oxide, nano silver, and carbon nanotubes (CNTs), were selected. We tested 48 samples, such as dust, sludge, ash, and by-products from manufacturing facilities and waste treatment facilities. We analyzed leaching and content concentrations for heavy metals and hazardous constituents of the waste. Chemical compositions were also measured by XRD and XRF, and the unique properties of nano-waste were identified by using a particle size distribution analyzer and TEM. The dust and sludge generated from manufacturing facilities and the use of nanomaterials showed higher concentrations of metals such as lead, arsenic, chromium, barium, and zinc. Oiled cloths from facilities using nano silver revealed high concentrations of copper, and the leaching concentrations of copper and lead in fly ash were higher than those in bottom ash. In XRF measurements at the facilities, we detected compounds such as silicon dioxide, sulfur trioxide, calcium oxide, titanium dioxide, and zinc oxide. We found several chemicals such as calcium oxide and silicon dioxide in the bottom ash of waste incinerators.

• Journal of Food Hygiene and Safety
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• v.36 no.4
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• pp.281-288
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• 2021

This study was conducted to analyze and compare the concentrations of heavy metals in 430 different products of 20 types of herbal medicines available in the domestic market in Korea by Graphite Furnace-Atomic Absorption Spectrometry (GF-AAS) and automated mercury analyzer. The accuracy for lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) was in the range 92.67-102.56%, and the precision was 0.21-6.00 relative standard deviation (RSD%), which was in compliance with the Codex acceptable range. Furthermore, the Food Analysis Performance Assessment Scheme (FAPAS) quality control (QC) material showed a recovery range of 96.7-102.0% and 0.33-4.93 RSD%. The average contents (㎍/kg) of Pb, As, Cd, and Hg in herbal medicines were 254.9 (not detected (N.D.)-2,515.2), 171.0 (N.D.-2,465.2), 99.2 (N.D.-797.1), and 6.0 (N.D.-83.6), respectively. Based on the quantitative analysis results, the heavy metal contents of 20 types of herbal medicines distributed in Korea are within the acceptable range according to the standards issued by the Ministry of Food and Drug Safety (MFDS). By using the manufacturer of herbal products as the standard for QC, the Pb, As, Cd, and Hg contents were investigated in the packaging process just before distribution to determine the actual conditions of residual heavy metals in herbal medicines. Thus, these result may contribute to monitoring the QC of herbal medicines distributed in Korea and could provide basic data for supplying safe herbal medicines to the public.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.409-419
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• 2023

Acid mine drainage(AMD) treatment is classified as both passive and active treatment. During the treatment, about 5,000 tons of neutralization sludge is generated as a by-product per year in Korea. This study was conducted to evaluate the characteristics of sludge generated from physico·chemical treatment processes as an active treatment from 5 different sources (D, H, S, T, Y) and the possibility of the sludges being recycled. The sludges have a pH range of 5.86 ~ pH 7.89, and a water content range of 51% ~ 82%. Most of particle sizes were less than 25 ㎛. In analysis of inorganic elements, the concentration of Al, Fe, and Mn were between 1,189 mg/kg ~ 129,344 mg/kg, 106,132 mg/kg ~ 338,011 mg/kg, and 3,472 mg/kg ~ 11,743 mg/kg, respectively. The concentration of As and Zn in sludge-T, Cd in sludge-D, Ni in sludge-H, Zn in sludge-S, and Cd in sludge-Y exceeded the soil contamination standards of Korea. The results from 2 separate kinds of leaching test, the Korea Standard Leaching Test(KSLT) and Toxicity Characteristic Leaching Procedure(TCLP), showed that all the sludges met the Korea groundwater standards. From the XRD and SEM-EDS analysis, the peaks of calcite and quartz were found in the sludges. The sludge also had a high proportion of Fe and O, and the majority of the composition was amorphous iron hydroxide.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.617-625
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• 2013

The present study was carried out to assess dietary exposure and risk for the infant population by lead (Pb), cadmium (Cd), and arsenic (As) exposure through modified milk powder and formulas. Analysis of heavy metals was performed using a microwave device and inductively coupled plasma-mass spectrometry, the method for which was fully validated. Various samples (n=204), including modified milk powder, modified milk, follow-up modified milk powder, infant formula and follow- up formula, were collected from retail outlets and markets across Korea. The mean contents of heavy metals were Pb 0.0004 (modified milk)-0.010 (infant formula) mg/kg, Cd 0.002 (modified milk)-0.007 (follow-up formula) mg/kg, and As 0.004(modified milk)-0.040 (infant formula) mg/kg, respectively. For risk assessment, daily intakes of heavy metals through maximum intake of modified milk powder and formulas were calculated and compared with reference doses established by JECFA and WHO. The dietary exposures of heavy metals were $0.78-1.04{\mu}g$ Pb/d, $0.65-0.87{\mu}g$ Cd/d, and $2.25-3.00{\mu}g$ As/d, corresponding to 2.0-4.5%, 7.1-16.0%, and 0.4-0.9% of reference doses, respectively. Therefore, the level of overall dietary exposure to heavy metals for Korean infant through food intake was below 20% of the reference dose, indicating a low risk to infant consumers.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.2
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• pp.80-84
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• 1994

The objective of this study was to find out the relationships between the vertical distribution of heavy metals in paddy soils and some soil characteristics. One hundred eight soil samples were collected by soil depths from 27 points of paddy fields in the vicinity of lead-zinc mining sites, and heavy metal contents and the physico-chemical characteristics of the soils were analysed. The results obtained were summarized as follows; 1) Distribution of heavy metals (Cd, Cu, Pb, Zn and As) by soil depths were ranged 42-51% in 0- 15 cm, 21-29% in 15- 30 cm, 12- 17% in 30-60 cm and 11-14% in 6o-100 cm. 2) The distribution of As by soil depth showed clear difference between sandy loam and loam, while that of Cd, Cu, Pb and Zn did not show any difference between these textures. 3) Distribution of Cd, Cu, Pb, Zn and As by different soil depths showed significantly negative correlation with soil pH value but they showed significantly positive correlation with soil organic matter content. 4) Cadmium, copper, lead, and zinc in soil had tendency to be highly correlated in each soil depth. Especially, high correlation was shown at the depth of 0- 15 cm, 30-60 cm and 60-100 cm for Pb and Zn, and 0-15 cm for Cd and Zn. Arsenic in soil was not correlated with these heavy metals.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.93-108
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• 2013

This study is aimed to prepare the effective detail survey methods(Phase II) of abandoned metal mines through the contamination assessment for mine types and facilities in the abandoned metal mine areas. The study sites of 12 abandoned mines are located in Gyeonggi-do and Gangwon-do and those were chosen among 310 sites that the Phase II survey was conducted from 2007 to 2009 after considering the results of Phase I for abandoned mines scattered all over the country. 12 study sites were classified into four types; Type I sites only have pit mouth. Type II sites have pit mouth and mine-waste field. Type III sites have pit mouth and tailing sorting field. Type IV sites have pit mouth, tailing sorting field and concentrator(s). In forest land, paddy soil and farm land of Type I, As and Cd were showed average concentration, and Cu and Pb were high on the pit mouth area in one mines where the pit mouth was developed within 500 m. In the mines of Type II, Cu and Pb were showed average concentration too, but As and Cd were slightly high in pit mouth and mine-waste field. The mines of Type III which had grinding particle process through physical separation milling or hitting showed similar tendency with Type II. However, mines of Type IV pit mouth, mine-waste field and showed various results depending on defining the contamination sources. For example, if contamination source was pit mouth, the mixed results of Type I, II, II were showed. In tailing sorting field which was regarded as the most important source and having high mobility, however, if there were no facilities or it was difficult to access directly, field sampling was missed occasionally during phase I and phase II survey. For that reason, the assessment for tailing sorting field is missed and it leads to completely different results. In the areas of Type I mines, the concentration of heavy metals exceeded precautionary standards of soil contamination or not within 1,000 meters of pit mouth. Nickel(Ni) was the largest factor of the heavy metal contamination in this type. The heavy metals except Arsenic(As) were shown high levels of concentration in Type II areas, where pit mouth and mine-waste field were operated for making powder in upriver region; therefore, to the areas in the vicinity of midstream and downstream, the high content of heavy metals were shown. The tendency of high level of heavy metals and toxic materials contained in flotation agent used during sorting process were found in soil around sorting and tailing field. In the abandoned-pit-mouth area, drygrinding area and tailing sorting field area, the content of Cupper(Cu) and Zinc(Zn) were higher than other areas. Also, the contaminated area were larger than mine reclamation area(2,000 m) and the location of tailing sorting field was one of the important factors to estimate contaminated area.

• Journal of Nutrition and Health
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• v.34 no.1
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• pp.48-53
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• 2001

As the severity of environmental pollution increases, the foodstuffs are contaminated more the ever. There are 40 kinds of heavy metals that we are able to consume through the heavy metal contaminated-foodstuffs. Arsenic, lead, cadmium, and chromium out or them have been know to be a potential cause for a alzheimers disease, kidney diseases, and cancer. However, research data on the daily intakes of such heavy metals are limited. This study was performed to evaluate the daily intakes of nutrients and the dietary heavy metals of the college women living in Choongchung-NamDo Area, where had been reported to have high contents of heavy metals for the seafoods. We also investigated the blood levels of the heavy metals. The mean age, height, weight, BMI and percent ideal body weight(PIBW) of the subjects were 20$\pm$1.0yr, 158.4$\pm$0.7cm, 55.1$\pm$1.4kg, 22.4$\pm$.04, and 103.3$\pm$2.5 %, resp-ectivly. The mean of daily energy intake was 1,717.03$\pm$55.99kacl/day(86% of RDA for women). The ratio to energy from carbohydrate, fat and protein was 60: 24: 16. Daily intakes of Vit A, Vit B$_2$, CA, and Fe were under the RDA for those nutrients. The mean adequate ratio of the subjects was 0.92 . The daily intakes of heavy metal, such as As, Pb, Co, Cr and Mn , were 1.80$\pm$0.27mg, 75.21$\pm$4.12$\mu\textrm{g}$, 21.12$\pm$12.34$\mu\textrm{g}$, 60.07$\pm$6.24$\mu\textrm{g}$ and 6.23 $\pm$0.12mg respectively. the blood levels of As, Pb, Co, Cr and Mn were 16.10$\pm$2.10$\mu\textrm{g}$/dl, 4.32$\pm$0.58$\mu\textrm{g}$/dl, 0.02$\pm$0.01$\mu\textrm{g}$/dl, 4.23$\pm$0.41$\mu\textrm{g}$/dl, and 4.40$\pm$0.21$\mu\textrm{g}$/dl, respectively. In conclusion, daily intake of heavy metals for the college women living in Choongchung-NamDo area was lower than that of WHOs re-commendation, however, the blood levels of each heavy metals were higher than those of Japanese, american, and italian, There were no correlations between the dietary intakes and blood levels of each heavy metals. (Korean J Nutrition 34(1):48-53, 2001)

• Food Science and Preservation
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• v.12 no.2
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• pp.107-111
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• 2005

We investigated the quality of vaporized liquid of water-boiled pine needle in the aspects of drinking conformity and aroma characteristics. As a result, there was no hazardous component in the assessment for 45 types of ingredients. Especially, inorganic components such as arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) which are harmful to human body were not detected. Additionally, we observed that other ingredients were present within the standard level suitable for drinking. The total 34 volatile components of the vaporized liquid of water-boiled pine needle were identified by dynamic head-space method. Fenchol, bomeol $\beta-fenchyl$ alcohol and bomyl acetate were the major volatiles and composed of 6.7, 13.1, 26.6 and $16.2\%$ of total volatiles, respectively. In addition, the alcohols and aldehydes were the prominent ingredients of which the contents showed comparatively high.